The treatise analyzes population and sexual conduct through physiology, moral reasoning, and political economy, arguing that knowledge of biological functions should shape social policy and family life. It outlines core principles, examines economic and social consequences of reproductive patterns, and links physiological evidence to obligations and purposes of marriage. Practical guidance addresses married couples, discusses institutions that care for abandoned children, and proposes measures aimed at preventing social ills. Editorial commentary situates these arguments within contemporary debates about utility, public health, and moral reform.